This field of art of this disclosure is an interspinous process implant.
The spinal column is a biomechanical structure composed primarily of ligaments, muscles, vertebrae and intervertebral disks. The biomechanical functions of the spine include: (1) support of the body, which involves the transfer of the weight and the bending movements of the head, trunk and arms to the pelvis and legs, (2) complex physiological motion between these parts, and (3) protection of the spinal cord and the nerve roots.
As the present society ages, it is anticipated that there will be an increase in adverse spinal conditions which are characteristic of older people. By way of example, with aging comes an increase in spinal stenosis (including, but not limited to, central canal and lateral stenosis), and facet anthropathy. Spinal stenosis typically results from the thickening of the bones that make up the spinal column and is characterized by a reduction in the available space for the passage of blood vessels and nerves. Pain associated with such stenosis can be relieved by medication and/or surgery.
In addition, to spinal stenosis, and facet anthropathy, the incidence of damage to the intervertebral disks due to injury or degeneration is also common. The primary purpose of the intervertebral disk is as a shock absorber. The disk is constructed of an inner gel-like structure, the nucleus pulposus (the nucleus), and an outer rigid structure comprised of collagen fibers, the annulus fibrosus (the annulus). At birth, the disk is 80% water, and then gradually diminishes, becoming stiff. With age, disks may degenerate, and bulge, thin, herniate, or ossify. Additionally, damage to disks may occur as a result spinal cord trauma or injury.
Given an increasing need, there is increasing attention currently focused on devices and methods for remediation of conditions of the spine. Remediation includes replacement or repair, or both of an affected part or parts of the spine, as will be discussed in more detail subsequently. Regarding the evolution of remediation of damage to intervertebral disks, rigid fixation procedures resulting in fusion are still the most commonly performed, though trends suggest a move away from such procedures. Currently, areas evolving to address the shortcomings of fusion for remediation of disk damage include technologies and procedures that preserve or repair the annulus, that replace or repair the nucleus, and that utilize technology advancement on devices for total disk replacement. The trend away from fusion is driven by both issues concerning the quality of life for those suffering from damaged intervertebral disks, as well as responsible health care management. These issues drive the desire for procedures that are minimally invasive, can be tolerated by patients of all ages, especially seniors, and can be performed preferably on an out patient basis.
Accordingly, there is a need in the art for innovation in technologies and methods that advance the art in the area of minimally invasive intervertebral disk remediation, thereby enhancing the quality of life for those suffering from the condition, as well as responding to the current needs of health care management.